Many existing optical fiber transmission systems use multi-mode optical fiber. Multi-mode optical fiber is widely used because it is relatively inexpensive, easy to install and because it is suitable for use with low cost transmitter and receiver components. The relatively large optical fiber core and numerical aperture of multi-mode optical fibers allows more light to be launched into the optical fiber, as compared to single-mode optical fibers. Therefore, such systems can use lower power and lower cost optical sources. For these reasons, local area networks have employed multi-mode optical fiber for many years. Some data communication systems, such as Fiber Data Distribution Interface (FDDI) systems are specifically designed to use multi-mode optical fiber. Known multimode optical fiber transmission systems, however, have relatively low bandwidth-distance products for a given bit error rate (BER) and, therefore, are not suitable for many state-of-the art communication systems.